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sustainability

Wood: renewable construction material of the future?

When you think "sustainability," building with wood isn't necessarily the first thing that comes to mind. But a deeper look at the growing trend begs the question: Could wood be a key sustainable resource of our future?

Travel to a developing country, and once you get off the beaten path and out into any forested area, you are likely to see truckloads of felled trees being ferried away.

Wood comes from forests — so typically, timber is associated with deforestation. And deforestation is a key environmental problem: not only does it destroy ecosystems and habitat; it's also a major factor driving climate change.

So wood isn't an obvious choice for eco-friendly construction. But with man-made materials leaving a huge carbon footprint, wooden architecture is enjoying a resurgence.

It's even being touted as our only significant renewable construction material.

Secondary forests, sustainably managed

To assess sustainability, the entire life cycle of a product must be considered. And that starts with the source. If primal forests are clear cut to provide timber — be they in the Amazon, Indonesia or the Pacific Northwest of the United States — that does not represent a sustainable source.

But in many densely populated parts of the world, including in Central Europe, people have used forests for many generations, and changed them in the process.

"Our European forests have been used for centuries, and are highly humanized in many ways," says Marc Palahí, director of the European Forest Institute, an international research organization.

Most European forests have been cut down, have grown back, and been cut down again

In Germany, for example, most forest is secondary, meaning it's been cut down and has regrown.

Timber extraction meant German forests were already shrinking in the 18th century, and foresters responded by considering how to manage them sustainably.

German forester Bernd Sommerhäuser explains the fundament of sustainable forestry: "What's used does not exceed what grows back — constant conservation is the goal."

Sommerhäuser says intervention in German forests isn't just sustainable — it's actually essential to preserve their biodiversity. "If we were to leave the forest over to itself here, it would normally develop into a stand of pure beech trees."

Building carbon-neutral(ish)

Once upon a time, wood was a primary building material across much of the world. But with industrialization, that changed in the West.

German architect Arnim Seidel explains that steel and concrete became the dominant building materials for to meet 20th-century demands: wide bridges, tall buildings, heavy loads.

"Wood came to be seen as backwards," Seidel told DW.

Concrete and steel rose to prominence to meet the needs of industrialized socieies - but their carbon footprint is huge

By some estimates, producing a ton of concrete, or about a cubic meter, generates 410 kilograms of CO2 equivalent — the same amount of energy could power an average house for more than 10 days.

Locally harvested wood from sustainably managed forests not only has a much smaller carbon footprint in its production.

Using wood in buildings also sequesters carbon dioxide. When plants perform photosynthesis, this removes CO2 from the atmosphere and stores it in the wood.

"When we build with wood, we can conserve this stored CO2 for a longer period of time, and not emit it into the atmosphere," Seidel told DW.

Building with wood, a growing trend

Wood has many benefits when it comes to construction: It's relatively lightweight and flexible, but also strong. It can be molded into various shapes, and is easy to transport to construction sites. Seidel says the possibilities of building with wood are virtually limitless.

The sky's the limit in building with wood - literally. Hamburg's Hafencity is planning a wooden skyscraper

Wooden skyscrapers are springing up in Canada, the United States and cities across Europe. Seidel describes these as "lighthouse projects" for sustainable building with wood.

But more mundane projects make up the bulk of wooden construction — even if they draw less attention. In Germany, about a quarter of residential homes and apartment buildings are now being built out of wood.

For public relations consultant Susanne Roth, sustainability — including carbon sequestration — was a major reason to invest in a multistory cohousing apartment on the outskirts of Bonn.

Roth also describes an emotional bond with wood, as she loves to be in the forest

Although there's not a lot of wood visible, the building — which consists of eight apartments — uses 190 cubic meters of wood, amounting to 190 tons of CO2 pulled out of the atmosphere. That's equivalent to taking about 40 cars off the road.

Countries with governance problems are often racked by illegal logging, such as here in Myanmar

Then, there's only so much secondary forest that can be harvested and replanted. So what happens when demand exceeds supply?

"We need to ensure that the few old forests we have in Europe — because in Europe, we have very few primal forests — are preserved," Palahí says.

So, no clear-cutting of old-growth forests. One possibility would be to plant more trees, which would also help the climate.

Palahí says we need to "compromise between using the forest for wood and at the same time preserving biodiversity."

Forests don’t just harbor biodiversity. They also protect water sources and sustain soils. Beyond that, they could increasingly provide the building blocks of the future bioeconomy — an economic system based on renewable, bio-based resources.

"European forests are important sources of renewable biological resources, which we will need to replace the existing petroleum-based steel and concrete if we want to address the problem of climate change," Palahí says.

The diversity of natural resources

Glorious and useful

While the world still produces a lot of its energy from fossil fuels, nature produces plenty of renewable resources constantly. Although plant lovers enjoy sunflowers for their splendour and chefs use the oil for cooking, industry uses the tall yellow flower to produce lubricants or in biodiesel. The sunflower is a renewable resource that is grown on about 400,000 hectares of farmland in Germany.

The diversity of natural resources

One of the oldest resources

Forests supply a resource mankind has been using for a very long time: wood. To whittle spears or to kindle a fire - wood was indispensable for our ancestors. It is still a popular building material: About 15 percent of new buildings in Germany are constructed out of wood.

The diversity of natural resources

Raw materials produce heat

Wood is a renewable resource that also supplies energy. Over the past decade, wood pellets have become increasingly popular to heat stoves - a good example for how renewables as an energy source can reduce mineral oil consumption.

The diversity of natural resources

A lubricant for steam engines

Rapeseed is a member of the cabbage family. Humans have been using the plant for many centuries. The seed has been a source for oil since the Middle Ages, used for instance in lamps. In the 19th century, rapeseed oil was used as a lubricant for steam engines.

The diversity of natural resources

The downside of the biogas boom

Using renewable resources as an energy supplier has given rise to quite some criticism. Huge fields of corn and rapeseed are planted to run biogas plants. As a result, the landscape in regions like northeastern Germany has radically changed, and many wild plants and animals have lost their habitat.

The diversity of natural resources

The all-rounder

Corn, originally from Latin America, is one of the most widely cultivated crops in the world. It is not just planted on vast fields for renewable energy purposes: its main use is animal feed and food for humans. Industry has also discovered corn as an ingredient for glue and adhesives.

The diversity of natural resources

Plant-based plastics

Plastic made of corn, potatoes or sugar cane: nowadays, many products are made of bioplastics, including garbage bags and joghurt containers, but also products such as disposable razors. Environmental activists support improving and consistently recycling bioplastics to ensure they are really environmentally friendly.

The diversity of natural resources

From biscuits to biodiesel

Palm fruit is pressed to win palm oil, an edible vegetable oil. It is an ingredient in many different types of food, including margarine, pizza and biscuits. Palm oil is used as a raw material in candles, cosmetics and washing powder. The product is also increasingly used for biodiesel production.

The diversity of natural resources

Palm trees replace rainforests

Palm oil is the one renewable resource that is most strongly criticized. Oil palms grow well in hot, humid climates, just like rainforests, rich in species and home to rare animals such as orangutans. Over the past years, rainforests have been felled extensively in Malaysia and Indonesia to make way for palm oil plantations.

The diversity of natural resources

Weaving, not smoking

Many people know hemp only as a recreational drug. But there is a form of hemp for industrial use that has no intoxicating effect. It is grown, for instance, in France, where the fibers are used to make special paper and clothing, like hemp jeans.

The diversity of natural resources

Keeping the heat in

Insulating material can also be made of hemp fiber. The blocks here can't be used on the outside of a house because they don't tolerate moisture, but the hemp is well-suited to insulate walls, ceilings or the roof of a house from the inside. Hemp fibers also help keep the house cool in the summer.